This invention relates to a facsimile transmitter (preferably but not necessarily portable) capable of transmitting pictures to a remote receiver by means of a telephone wire or wireless transmission line.
Prior art transmitters of this type commonly employ a rotating drum to which the original picture to be transmitted is affixed by means of detachable clamps, and an optical system for scanning along a line parallel to the drum axis and coupling the resulting video output to a (wire or wireless) telephone transmission line.
In such prior art systems, in order to affix pictures of varying sizes to the drum, it is necessary to detach the clamps, place the picture on the drum, and reinstall the clamps. This procedure is a cumbersome one, and the clamps are readily misplaced or lost.
These prior art systems, moreover, exhibit limited quality of picture transmission. Further, malfunctions which occur during transmission result in the wasting of expensive telephone time, since the prior art units normally continue to transmit faulty picture information under such circumstances.
An additional disadvantage of prior art facsimile systems is that such systems begin the transmission at a fixed longitudinal line on the drum, so that regardless of the size of the original, the copy made at the remote receiver is disposed adjacent the leading edge of the sheet on which the copy appears, resulting at times in a reduction of copy quality.
Accordingly, an object of the present invention is to provide an improved facsimile transmitter which overcomes the foregoing and other disadvantages of prior art units of this type.